? The development of low polarization electrode coatings for cardiac pacing, sensing and defibrillation is proposed. These coatings address the needs of the cardiac rhythm management (CRM) industry in the development of low-polarization pacing, low impedance defibrillation, and post-stimulus sensing methodologies. The coatings are based on films of sputtered iridium oxide (SIROFs) and IrTi-oxide with tailored surface morphologies that maximizes low-polarization charge-injection. The addition of titanium to form a mixed, IrTi-oxide significantly enhances the chemical and physical stability of the coatings without compromising pacing and sensing performance. The development of IrTi-oxide in Phase I is considered significant, since it provides a means through siloxane chemistry to covalently attach a broad range of functional organic species to the surface of the electrode to enhance biocompatibility and moderate inflammatory responses. The Phase II Aims are 1) To develop robust, low-cost coatings for cardiac electrodes that reduce pacing thresholds and permit reliable sensing of cardiac electrical activity; 2) To develop organically functionalized coatings for cardiac electrodes that reduce fibrotic tissue encapsulation and lower pacing thresholds relative to non-functionalized electrodes, and 3) To develop low-impedance coatings that reduce defibrillation thresholds (DFTs) of implantable cardioverter defibrillator (ICD) electrodes. Reduced thresholds and improved sensing will benefit the patient by enhancing the efficacy of the implant and by increasing the time between surgical procedures necessary to replace batteries. The SIROF and IrTi-oxide will be lower cost than competing coating materials (e.g. TiN), making them attractive commercially. In Phase II, in vitro assessments of the anti-inflammatory properties of covalently functionalized organic surface coatings will be made and these coatings evaluated for long-term stability by accelerated in vitro testing. The performance of SIROF, IrTi-oxide and functionalized IrTi-oxide for pacing and defibrillation will be assessed experimentally. As a step towards clinical implementation, the more optimum coatings will be evaluated for chronic pacing in a sheep model and for reduced DFTs in an acute pig model. The in vivo studies will be done with collaborators at the University of Alabama. ? ?

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Small Business Innovation Research Grants (SBIR) - Phase II (R44)
Project #
2R44HL071395-02
Application #
6934439
Study Section
Special Emphasis Panel (ZRG1-SBTS (10))
Program Officer
Dunn, Rosalie
Project Start
2002-09-10
Project End
2007-06-30
Budget Start
2005-09-16
Budget End
2006-06-30
Support Year
2
Fiscal Year
2005
Total Cost
$685,377
Indirect Cost
Name
Eic Laboratories, Inc.
Department
Type
DUNS #
076603836
City
Norwood
State
MA
Country
United States
Zip Code
02062
Cogan, Stuart F; Ehrlich, Julia; Plante, Timothy D et al. (2010) Contribution of oxygen reduction to charge injection on platinum and sputtered iridium oxide neural stimulation electrodes. IEEE Trans Biomed Eng 57:2313-21
Cogan, Stuart F; Ehrlich, Julia; Plante, Timothy D et al. (2009) Sputtered iridium oxide films for neural stimulation electrodes. J Biomed Mater Res B Appl Biomater 89B:353-61
Cogan, S F; Plante, T D; Ehrlich, J (2004) Sputtered iridium oxide films (SIROFs) for low-impedance neural stimulation and recording electrodes. Conf Proc IEEE Eng Med Biol Soc 6:4153-6